Questions tagged [uart]
A UART (Universal Asynchronous Receiver Transmitter) is a piece of logic that sends and receives data on a serial port.
1,718 questions
0 votes
1 answer
98 views
What is this LCD UART module?
I have some old typical 16x2 LCD character displays. Two of them have an extra UART board attached but I cannot find any documentation on them at all. They expose 2 positive pins, 2 negative pins, 2 ...
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6 votes
2 answers
687 views
UART on custom STM32 Microcontroller board outputs garbage data
Recently, got a custom STM32F103CBT6 microcontroller board manufactured and got a basic GPIO pin to blink an LED. However, once I started trying to output simple messages via a UART port, using a HC-...
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0 votes
1 answer
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Why are pull-up resistors provided on the UART lines of the AM62L EVM?
I was reviewing the AM62L EVM (Evaluation Module) schematic and noticed that the UART lines (TX, RX) have external pull-up resistors to 3.3 V. However, when I checked the AM62L datasheet and technical ...
2 votes
0 answers
83 views
PIC16F18456 USART outputting 11bits despite TX9 set to 0
A strange issue that appears to be an obvious fix at first, but I have tried the usual suspects... My goal is to build a simple UART bridge on a PIC16F18456 (without XTAL). RX data on USART1 and TX ...
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1 vote
1 answer
78 views
STM32 F302R8 UART RX reception error
I'm new in the STM32 world. I’m currently testing basic UART communication on an STM32 (STM32F302R8) with an HC-05 Bluetooth module, and I’m running into a strange issue with receiving data. I'm using ...
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6 votes
3 answers
892 views
UART as RS485 with Linux
I have been working on multiple projects of Embedded Linux from last 5 years but there is a small problem when I use UART. I am using STM32MP13F with MYIR board. The UART is connected to half duplex ...
1 vote
1 answer
81 views
Why does the USART count in STM32 MCU differ between datasheet and IDE?
Regarding this STM32 MCU family (in my case STM32F303K8T6), in the datasheet there is the following statement about UART peripherals: If I'm not wrong it says this MCU has three USARTs. But when I ...
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1 vote
1 answer
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UART buffer mostly filled with garbage data (STM32F7)
Basic setup information: I have a Nucleo-F767ZI connected to my PC through the USB cable which is also used for its virtual com port. All the peripherals have been iniitalised to their default mode. I ...
0 votes
1 answer
104 views
STM32 UART in Interrupt mode misses data?
I am working with STM32F7 mcu running at 160 MHz, I am also running UART at 160 MHz in interrupt mode to receive data, but in DMA mode to send data. My program also runs 3 SPI and 1 I2C in DMA mode to ...
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-1 votes
1 answer
69 views
Integrating Polling-Based Modules with UART Interrupt Communication on STM32 – Any Risks? [closed]
I'm developing a project using an STM32 Nucleo board. At the core of this project is a UART-based communication protocol running in interrupt (IT) mode — not polling or DMA. This protocol is ...
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1 vote
1 answer
81 views
USART Rx DMA request not being generated, although data is being received [duplicate]
I've been banging my head on a wall for a shameful amount of time trying to understand why USART is not invoking DMA to transfer bytes from its Rx buffer into a memory buffer: ...
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1 answer
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Will disconnecting USB host make the device go into "Suspend" mode (CH340G)
I've a sensor MCU which cannot be reprogrammed. That MCU constantly sends values over Serial and doesn't care if there is another device listens or not. The whole device is powered by an onboard AC-DC ...
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1 vote
1 answer
75 views
Protect ESP32 from Overvoltage via External UART Connection
I have a TJC HMI display similar to Nextion. It communicates with the ESP32 through UART. The display operates at 5V, but the specification table indicates that the Tx and RX pin voltages are 3.3V, ...
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0 votes
2 answers
192 views
ESD Protection for UART and I2C
I am designing a PCB board that features the ESP32 as the microcontroller. The UART pins will connect to an external HMI LCD, specifically the TJC (a Chinese version of Nextion), through a screw ...
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2 votes
2 answers
173 views
Adjusting the pulse width of a comparator output
This question is a continuation of a question which I asked earlier in this forum.We are doing a discrete circuit implementation of an IrDA transceiver.This question is also related to it. We made the ...
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